氯沙坦协同辛伐他汀对心力衰竭大鼠心室基质金属蛋白酶2、9及其组织抑制因子1、2基因表达的影响

目的 探讨心力衰竭(心衰)时心脏基质金属蛋白酶2(MMP-2)、9(MMP-9)及其组织抑制因子1(TIMP-1)、2(TIMP-2)基因表达及其与心肌纤维化的关系.方法 用降主动脉缩窄术建立心衰模型.SD大鼠随机分成6组.分别在氯沙坦5 mg/kg、辛伐他汀2 mg/kg以及两药合用(联合投药组)投药后1、3,5周动态测定左室舒张末期内径、左室收缩末期内径及左室后壁厚度、左室短轴缩短率.ELISA法检测B型利钠肽浓度.Masson染色观察心肌胶原情况.RT-PCR法检测心室MMP-2、MMP-9和TIMP-1、TIMP-2基因表达.结果 投药后5周各组胶原容积分数比较差异有统计学意义(P<0.01),投药各组较降主动脉缩窄(模型)组下降(P<0.05),尤其联合投药组下降更明显(P<0.01).MMP-2 mRNA和MMP-9 mBNA在投药各组与模型组差异无统计学意义(P>0.05);但TIMP-1 mRNA和TIMP-2 mRNA在投药各组明显低于模型组(P<0.01),联合投药组降低更明显(P<0.05).结论 心衰模型大鼠MMP-2 mRNA、MMP-9 mRNA和TIMP-1 mRNA、TIMP-2 mRNA表达升高可能是压力负荷大鼠心肌胶原含量增加的分子机制之一,氯沙坦、辛伐他汀以及联合投药均能下调TIMP-1 mRNA、TIMP-2 mRNA水平,缓解心肌重构,尤其联合投药组效果更明显.

Effects of losartan and simvastatin on collagen content, myocardial expression of MMP-2 mRNA, MMP-9 mRNA and TIMP-1 mRNA, TIMP-2 mRNA in pressure overload rat hearts

Objective To investigate the effects of simvastatin(Sim) and losartan(Los) on cardiac fibrosis and myocardial expression of MMP-2 mRNA, MMP-9 mRNA and TIMP-1 mRNA, TIMP-2 mRNA in pressure overloaded rat hearts. Methods The pressure overload model was induced by descending aortic constriction (DAC) in rats. SD rats were randomized into 6 groups (n=20 each) : normol control group, control sham group, DAC group, Los group (DAC+Los, 5 mg/kg), Sire group ( DAC + Sire, 2 mg/kg), Los + Sire group (DAC+Los+Sire, Los 5 mg/kg, Sire 2 mg/kg). Water, Los or Sire drug was administrated by garage daily beginning from day 5 after operation for 30 days. Collagen was measured on Masson stained myocardial sections, and the level of MMP-2 mRNA, MMP-9 mRNA and TIMP-1 mRNA, TIMP-2 mRNA in left ventricle were detected by RT-PCR. Results Collagen volume fraction (CVF) in DAC group was significantly higher than the normal control and sham groups (P<0.01) which could be significantly reduced by Los and Sire (P<0.05), especially in DAC + Los + Sire group (P<0.01). The levels of myocardial MMP-2 mRNA, MMP-9 mRNA and TIMP-1 mRNA, TIMP-2 mRNA were also significantly higher in DAC group than in normal control and sham groups (P<0.01). Treatment Sim and Los alone and especially in combination significantly decreased the TIMP-1 mRNA, TIMP-2 mRNA expressions (P<0.01) while MMP-2 mRNA, MMP-9 mRNA levels remained unchanged (P>0.05). Conclusion Upregulation of myocardial MMP-2 mRNA, MMP-9 mRNA and TIMP-1 mRNA, TIMP-2 mRNA expressions might contribute to myocardial fibrosis in this model, Sire and Los significantly inhibited myocardial fibrosis possibly by downregulating myocardial TIMP-1 mRNA, TIMP-2 mRNA expressions in this model.